Integrative Physiology Ch. 2 - Molecular Interactions
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| Atom | The building block of matter; composed of positively charged protons, neutral neutrons, and negatively charged electrons. It contains an equal # of protons and electrons, hence an overall neutral charge
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| Nucleus | The dense body at the center of an atom in which the protons and neutrons are clustered. Virtually all of the atoms mass is accounted for in the nucleus. Electrons exist outside—around—the nucleus, moving rapidly
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| Diameter of an atom | 1 to 5 Angstroms
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| Atoms can be described in two ways: | By their atomic number and their atomic mass
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| Atomic number | The number of protons in the nucleus of an atom. This number determines what element and atom is.
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| Major essential elements in the context of human physiology | O, C, H (O/C/H = 90%), N, P, Na, K, Ca, Mg, S, Cl
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| Examples of some trace elements (AKA minor essential elements) | Se, Cr, Mn, Mo
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| Atomic mass | Total mass of the protons and neutrons in an atom; expressed in atomic mass units, where 1 amu = 1.6605e-27 kg. E.g. the He is equal to 4 amu (2 protons + 2 neutrons)
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| Isotopes | Atoms of the same element with differing numbers of neutrons. Indicated at the upper left of the chemical symbol. E.g. H has 3 isotopes: hydrogen, deuterium (1 proton, 1 neutron), and tritium
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| Radioisotopes | Unstable isotopes that emit energy called radiation.
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| Types of emitted radiation from radioisotopes | Alpha, beta, and gamma. Alpha and beta radiation consists of fast moving particles (protons/neutrons/electrons) while gamma radiation consists of high energy waves. Gamma radiation can penetrate matter more deeply
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| Shells | Energy levels in which electrons are arranged. Lowest energy shell = closest to nucleus. First shell has a limit of two electrons; the second has a limit of eight, and so on
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| Covalent bonds | Shared electrons form strong covalent bonds to create molecules
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| Ions | If an atom gains or loses electrons, it acquires an electrical charge and becomes an ion.
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| Anion | A negatively charged ion.
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| Cation | A positively charged ion.
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| Important ions of the body | Na+, K+, Ca^2+, H+, Mg^2+, Cl-, HCO^3-, HPO4^2-, SO4^2-
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| High energy electrons | Electrons in a higher energy state which can emit energy as they return to their ground state. E.g. bioluminescence in fireflies is visible light emitted by high-energy electrons returning to their ground state
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| Free radicals | Atoms with at least one unpaired e-. E.g. the electrically neutral hydroxyl free radical, OH (formed when OH- loses an e-), or the superoxide ion (dot)O2- (formed during metabolism when O2 gains an extra e-)
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| Antioxidants | Substances that can prevent damage to our cells by giving up electrons without becoming free radicals, hence ending the chain reaction of free-radical production. E.g. vitamin C and Vitamin E
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| Molecules | Units formed when two or more atoms bond by sharing electrons (covalently), e.g. the homonuclear diatomic molecule H2
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| Compounds | Units formed when two or more DIFFERENT atoms are bonded (either ionically or covalently), e.g. the diatomic compound ZnS
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| Four common bond types | Two strong types: ionic and covalent; and two weak types: H-bonds and Van der Waals
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| Double bonds | They occur when atoms share two pairs of electrons rather than one pair
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| Polar molecules | Molecules in which the electrons are shared unevenly. Thus regions of partial positive charge (delta-positive) and regions of partial negative charge (delta-negative) result. E.g. H2O is a polar molecule
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| Nonpolar molecules | Those molecules in which the electrons are shared evenly and no regions of partial positive or negative charges result. E.g. F2
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| Hydrophilic vs. hydrophobic in the context of solubility in water | Polar molecules, such as table sugar, are said to be hydrophilic and dissolve easily in water. Nonpolar molecules, such as oils, do not dissolve well in water and are said to be hydrophobic
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| Ion | When an atom completely gains or loses an electron, it becomes an ion
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| Ionic bonds | Occurs when an atom has such a strong attraction for electrons that it pulls one or more electrons completely away from another atom. The resulting ions are attracted to each other via their opposite charges
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| Hydrogen bond | A weak attractive force between a hydrogen atom and a nearby oxygen, nitrogen, or fluorine atom. E.g. surface tension in water is a result of hydrogen bonding
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| Van der Waals forces | Weak, nonspecific attractions between the nucleus of any atom and the electrons of nearby atoms. Van der Waals forces allow atoms to pack very closely together. A single attraction is weak, but multiple attractions are strong
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| Organic molecules | Molecules that contain carbon
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| Biomolecules | Organic molecules associated with living organisms
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| Four major groups of biomolecules: | carbohydrates, lipids, proteins, and nucleotides
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| Polymers | Large molecules made up of repeating units
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| Functional groups | Combinations of atoms that occur repeatedly in biological molecules
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| The four most common functional groups | Carboxyl (-COOH), Hydroxyl (-OH), Amino (-NH2), and Phosphate (-H2PO4)
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| From where is the name “carbohydrate” derived? | From their structure: carbons (carbo-) with water (hydro-). Note: they are the most abundant biomolecules
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| General formula for a carbohydrate | (CH2O)_n; e.g., n = 6 for water: C6H12O6
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| Carbohydrates occur as… | …simple sugars: monosaccharides/disaccharides, as well as complex sugars: polysaccharides
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| The most common monosaccharides | Ribose (5 carbons) and glucose (6 carbons). Note: glucose is AKA dextrose
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| How do living cells store glucose? | As polysaccharides: glycogen in animals; starch in plants; and dextran in yeasts/bacteria
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| Structural polysaccharides | Two examples: cellulose in plants and chitin in invertebrate animals. Note: humans cannot (unfortunately) digest cellulose even though it is the most abundant organic molecule on earth
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| Lipids | Biomolecules made up of carbon, hydrogen, and oxygen, but with much less oxygen than in carbohydrates. They are nonpolar and not very soluble in water.
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| Fats/oils | Lipids are technically called “fats” if they are solid at room temperature and are called “oils” if they are liquid at room temperature
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| The derivation of fats and oils | Most lipids derived from animal sources, such as lard and butter, are fats; most lipids derived from plants are oils
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| Within the category of lipids, three types of lipid-related molecules are included: | (1) phospholipids, (2) steroids, and (3) eicosanoids
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| Composition of “true” lipids | They contain a simple 3-carbon molecule known as a glycerol plus long molecules known as fatty acids. Note: phospholipids also include a phosphate group
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| Fatty acids | Long chains of hydrocarbons with a carboxyl group (-COOH) at one end of the chain
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| Saturated fatty acids | No double bonds
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| Monosaturated fatty acids | One double bond in the molecule
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| Polyunsaturated fatty acids | There are two or more double bonds in the molecule
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| Mono-, di-, and triglycerides | Glycerol links to one, two, or three fatty acids to form mono-, di-, or triglycerides, respectively.
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| Triglycerides | The most important form of lipid in the body with more than 90% of our lipids in this form. Note: an elevated triglyceride level in the blood serves as an important predictor of cardiovascular disease
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| Sucrose, Maltose, Lactose | Sucrose = fructose + glucose; maltose = glucose + glucose; lactose = galactose + glucose
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| Steroids | Lipid-related molecules whose structure includes four linked carbon rings.
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| _____ is the source of steroids in the human body, and is the basis for a number of important hormones. It’s also important because… | Cholesterol; …it serves as an important component of animal cell membranes
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| Eicosanoids | Modified 20-carbon fatty acids that are found in animals. These molecules all contain a complete or partial carbon ring at one end with two long carbon chain tails extending out from it
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| The main eicosanoids: | Thromboxanes, leukotrienes, and prostaglandins. Note: eicosanoids are regulators of various physiological functions
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| Proteins | Polymers of smaller building-block molecules called amino acids
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| How many amino acids commonly occur in natural proteins? How many of them can the human body synthesize? | 20; the human body can synthesize 11 of them (9 must be acquired from dietary proteins).
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| Essential amino acids | The 9 amino acids that the human body must acquire from dietary proteins for survival
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| Amino acids that DON’T occur in proteins but still have important biological functions | Homocysteine, gamma-amino butyric acid (GABA), and creatine
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| Homocysteine | A sulfur-containing amino acid that occurs normally in the body but which in excess is associated with heart disease
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| Gamma-amino butyric acid (GABA) | A chemical made by nerve cells
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| Creatine | A molecule that stores energy when it binds to a phosphate group
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| All amino acids have a similar core structure: | A central carbon atom is linked to hydrogen atom, a nitrogen-containing amino group (hence the name “amino” acid), a carboxyl group, and a group of atoms designated “R” that is different in each amino acid
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| What makes each amino acid unique in size, shape, ability to form H-bonds or ions, and behavior? | The R group
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| Peptide bond | When two amino acids link together, the amino group of one is joined to the carboxyl group of the other, forming a peptide bond
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| Peptide | The general name for any amino acid polymer, which refers to a polymer of any length, from two units to two million units
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| Different peptide polymers according to size | Oligopeptide: chain of 2 – 9 amino acids; polypeptide: chain of 10 – 100 amino acids; protein: chain of over 100 amino acids
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| Primary structure | The sequence of amino acids in a peptide or protein chain. The primary structure is genetically determined and is essential to proper function
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| Secondary structure | The spatial arrangement or shape of a polypeptide chain; it’s stabilized by H-bonding between different parts of the molecule
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| The three most common shapes for polypeptide bonds | (1) A spiral called the alpha-helix; (2) the beta-strand whose bond angles create a zigzag shape, and (3) U-shaped beta-turns.
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| Beta-strands | Beta-strands often assemble into side-by-side pleated sheets. Proteins that are destined for structural uses may be composed entirely of pleated sheets because this configuration is very stable
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| Tertiary structure | The three-dimensional shape of a protein. They’re categorized into two groups: fibrous and globular.
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| Fibrous proteins | Found as pleated sheets or in long chains of helices. They’re insoluble in water and form important structural components of cells and tissues. E.g.: collagen (found in connective tissue) and keratin (found in hair/nails)
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| Globular proteins | They have amino acid chains that fold back on themselves to create a complex tertiary structure containing pockets, channels, or protruding knobs. They’re soluble in water
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| From where does the tertiary structure of globular proteins arise? | Partly from the angles of covalent bonds between amino acids, and partly from hydrogen bonds, van der Waals forces, and ionic bonds that stabilize the tertiary structure
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| How does the amino acid cysteine play a role in globular protein shape? | Cysteine contains sulfur as part of a sulfhydryl group (-SH). Two cysteines in different parts of the polypeptide chain can bond covalently to each other in a disulfide (S-S) bond, pulling different sections of the chain together
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| Why is the water-solubility of globular proteins important? | They act as carriers for water-insoluble lipids in the blood, binding to the lipids and making them soluble.
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| Other functions of water-soluble globular proteins | They serve as enzymes. And they also serve as cell-to-cell messengers in the form of hormones/neurotransmitters and as defense molecules to help fight foreign invaders
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| Quaternary structure | If several protein chains associate with another to form a functional protein, the protein is said to have a quaternary structure. E.g. hemoglobin, which has four subunits, making it a tetramer
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| Conjugated proteins | Protein molecules combined with another kind of biomolecule. E.g. lipoproteins
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| Lipoproteins | Proteins combine with lipids to form lipoproteins, which are found in cell membranes, and they transport hydrophobic molecules, such as cholesterol, in the blood
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| Glycosylated molecules | Molecules to which carbohydrates have been attached, e.g. glycoproteins and glycolipids
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| Glycoproteins and glycolipids | Proteins combine with carbohydrates to form glycoproteins; Lipids bind to carbohydrates to form glycolipids. Like lipoproteins, glycolipids and glycoproteins are important in cell membranes
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| Nucleotide composition | A three-part molecule consisting of (1) one or more phosphate groups, (2) a 5-carbon sugar, and (3) a carbon-nitrogen ring structure called a nitrogenous base
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| Two types of 5-carbon sugars found in nucleotides | One of two possible sugars: either the ribose deoxyribose, which is a ribose minus one oxygen atom.
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| Two types of nitrogenous bases; list them | The purines and the pyrimidines. The purines have a double ring structure; the pyrimidines have a single ring. There are two purines: adenine and guanine and three pyrimidines: cytosine, thymine, and uracil
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| Nucleotides that are energy-transferring compounds | They are some of the smallest nucleotides: ATP, ADP, cyclic AMP, NAD, and FAD
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| DNA and RNA are… | …nucleotide polymers, or nucleic acids. They store genetic information within the cell and transmit it to future generations of cells. They’re formed by linking nucleotides into long chains.
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| DNA and RNA structure | The sugar of one nucleotide links to the phosphate of the next, creating a chain, or “backbone”, of alternating sugar-phosphate-sugar-phosphate groups. The nitrogenous bases, ATCG, extend to the side of the chain of DNA
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| DNA vs. RNA nitrogenous bases and overall conformation | RNA doesn’t have thymine, instead it has uracil. RNA is found as a single strand whereas DNA is a double helix, with the two strands linked by their nitrogenous bases via H-bonds
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| Due to the relative size/structure of the nitrogenous bases, the bases always pair with each other the following ways: | A-T, C-G
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| The human body is about __% water | 60%
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| The main ions in body fluids | Na+, K+, and Cl-; other ions make up a lesser proportion
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| Solutes | Substances dissolved in a liquid
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| Solvent | The liquid in which solutes dissolve
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| Solution | The combination of solutes and solvent
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| The universal solvent in biological solutions | Water
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| Solubility | The degree to which a molecule is able to dissolve in a solvent – the more easily it dissolves, the higher its solubility
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| Hydrophilic molecules | Molecules that can dissolve easily; most are polar or ionic, whose negative and positive partial charges interact with the water molecules
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| Hydrophobic molecules | Molecules that do not dissolve readily in water; they tend to be nonpolar and unable to make H-bonds
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| The most hydrophobic group of biological molecules | The lipids (fats and oils)
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| For hydrophobic molecules to dissolve in body fluids… | …they must be combined with a hydrophilic molecule that can effectively carry them into solution; e.g., cholesterol can only travel through body fluids if being carried by lipoprotein carrier molecules
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| Other properties of water that affect the way our bodies work | Surface tension and large heat capacity
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| Concentration of a solution | The amount of solute per unit volume of solution
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| Values used to express concentration | Mass: g or mg; number of solute molecules: mol; number of solute ions: eq (equivalents); volume: L or mL
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| Mole | 6.02e23 atoms, ions, or molecules of a substance. One mole of a substance has the same number of particles as one mole of any other substance. The mass of one mole of a substance depends on the substance being measured
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| Molecular mass | The mass of one molecule, expressed in atomic mass units. E.g. glucose = C6H12O6 = [(6*12)+(12*1)+(6*16)] = 180
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| Gram molecular mass | The mass of one mole of a substance (equal to the molecular mass expressed in grams, e.g. 1mol glucose = 180g)
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| Molarity | The number of moles of solute in a liter of solution, abbreviated as mol/L or M (molar). A 1 molar solution = 1M = 1 mol / L = 6.02e23 molecules of solute per liter of solution
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| Millimole | 1/1000 of a mole (expressed as mmole/L or mM)
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| Equivalent (eq) | Equal to the molarity of an ion times the number of charged the ion carries. E.g. a Na+ ion has one equivalent per mole. A Ca^2+ ion has two equivalents per mole. The Cl- ion has one equivalent per mole.
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| Milliequivalent (meq) | 1/1000 of an equivalent. Useful for expressing the concentration of dilute biological solutions. E.g. the concentration of sodium ions in the blood are reported as meq/L
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| In the lab or pharmacy, scientists cannot measure out solutes by the mole, instead they use… | Percent solution. E.g. a 10% solution means 10 parts of solute per 100 parts of TOTAL SOLUTION
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| For percent solution, if the solute is normally a solid at room temperature… | …the percent solution is expressed as weight of a solute per volume of solution. E.g. a 5% glucose solution has 5 grams of glucose dissolved in water to make a final volume of 100 mL of solution
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| For percent solution, if the solute is liquid as room temperature… | …the solution is made using volume/volume measurements. To make 0.1% HCl, for instance, add 0.1 mL of concentrated acid to enough water to give a final volume of 100 mL
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| Weight/volume convention which is common in medicine | The concentrations of drugs and other chemicals in the body are often expressed as milligrams of solute per deciliter of solution (mg/dL). A deciliter (dL) is 1/10 of a liter, or 100 mL. Note: archaic: 20 mg/dL = “20 mg%”
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| The concentrations of ___ in body fluids determines the body’s acidity | H+ (Hydrogen ions)
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| Why is the concentration of H+ closely regulated? | Because H+ can interfere with H-bonding and van der Waal forces. These bonds are responsible for the shapes of many important molecules, so disruption of the bonding can wreak havoc on the body
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| Where do hydrogen ions in the body originate? | Some of them come from the separation of water molecules (H2O) into H+ and OH- ions. Others come from molecules that release H+ when they dissolve in water
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| Acids | Molecules that contribute H+ to a solution; e.g. H2CO3
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| Bases | Molecules that decrease the free H+ concentration by binding to them; e.g. OH- or NH3
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| What does pH stand for? | Power of hydrogen
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| Calculation of pH | pH = -log[H+] or can also be written as pH = log(1/[H+]), where [H+] concentration of H+
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| Numeric scale for pH | From 0 to 14, where a number, e.g. 7 means that the H+ concentration is 1*10^-7, which is the pH of water. Water is considered neutral. Acidic solutions have pH less than 7. Basic (AKA alkaline) solutions have pH > 7
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| pH of blood | 7.4; slightly alkaline
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| Tight regulation of the body’s pH level is critical because… | …a blood pH more acidic than 7 or more alkaline than 7.7 is incompatible with life
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| How does the body maintain a normal pH despite all of the acidic nutrients we ingest? | Buffers.
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| Buffers. What do they consist of? | A buffer is any substance that moderates changes in pH. Many buffers contain anions that have a strong affinity for H+ molecules. When free H+ is added to a buffer solution, these anions bond to the H+
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| Example of an important buffer in the human body | HCO3- which binds with free H+ to form carbonic acid
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| Proteome | The protein equivalent of the genome – a catalog of all of the proteins in the body. Not yet complete
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| Most soluble proteins fall into seven broad categories: | Enzymes; Membrane transporters; Signal molecules; Receptors; Binding proteins; Regulatory proteins; Immunoglobins
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| Enzymes | Proteins that speed up chemical reactions
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| Membrane transporters | They help move substances back and forth between intracellular and extracellular compartments
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| Signal molecules | Proteins and smaller peptides that act as hormones and other signal molecules
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| Receptors | Proteins that bind signal molecules and initiate cellular responses
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| Binding proteins | Bind and transport molecules throughout the body, e.g. hemoglobin
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| Regulatory proteins | Regulatory proteins turn cell processes on and off or up and down
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| Immunoglobulins | Antibodies
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| Although soluble proteins are diverse, what do they have in common? | They all bind to other molecules through noncovalent interactions. The binding takes place on a part of the protein called the binding site, which exhibits specificity, affinity, competition, and saturation
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| Ligand | Any molecule that binds to another molecule
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| Substrate | Ligands that bind to enzymes and enzyme transporters
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| Ligand binding requires | Molecular complementarity; that is, the ligand and the binding site must be complementary, or compatible
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| Does the protein’s binding site and shape of its ligand have to fit each other exactly? | No, the induced-fit model prevails, which is that the protein will change shape a little bit to fit more closely to the ligand
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| Specificity | The ability of a protein to bind to a certain ligand or a group of related ligands
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| Peptidases | Enzymes that bind to polypeptides and break apart peptide bonds no matter which two amino acids are joined by those bonds. Thus, they’re not very specific
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| Aminopeptidases | Only binds to the very end of a polypeptide and act only on the terminal peptide bond
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| Affinity | The degree to which a protein is attracted to a ligand. High affinity = the protein is more likely to bind to that particular ligand compared to one with a low affinity
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| Protein binding to a ligand notation | P + L (double arrow) PL, where P is the protein, L is the ligand, and PL is the bound protein-ligand complex. The double arrow indicates that it’s reversible
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| Equilibrium state of protein-ligand binding, define | The state at which the rate of binding is exactly equal to the rate of unbinding, or dissociation.
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| Equilibrium constant for protein-ligand binding | Keq = ([P][L])/[PL]; AKA the dissociation constant (Kd). It can also be expressed as [PL] = ([P][L])/Kd
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| The relationship between [PL] and Kd | When Kd is large, [PL] is small. I.e. A large dissociation constant Kd means little binding of protein and ligand, and we can say the protein has a low affinity for the ligand
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| If a protein binds to several ligands, a comparison of their Kd values can tell us… | …which ligand is more likely to bind to the protein
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| Competitors | Related ligands that compete for the binding sites
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| Agonist | An enzyme that mimics another’s actions. They are found in nature as well as synthesized. The ability to synthesize them has led to the creation of many drugs
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| Nicotine | An agonist because it mimics the activity of the neurotransmitter acetylcholine by binding to the same receptor protein
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| Isoforms | Closely related proteins whose function is similar but whose affinity for ligands differs, e.g. hemoglobin vs. fetal hemoglobin. Both bind to oxygen but the fetal isoform has a higher affinity for oxygen
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| Proteolytic activation | Some proteins are inactive when they are synthesized in the cell. Before such a cell can become active, enzymes must chop off one or more portions of the molecule (Proteolytic activation).
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| Two groups that commonly undergo proteolytic activation. How can you identify inactive forms? | Protein hormones and enzymes. Inactive forms often can be identified with the prefix pro- (e.g. prohormone, proenzyme, proinsulin, etc.). Some other inactive forms have the suffix -ogen, e.g. chymotrypsinogen
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| The activation of some proteins requires the presence of… | …a cofactor, which is an ion or small organic functional group. Cofactors must attach to the protein before the binding site will bind to the ligand. Ionic cofactors include Ca^2+, Mg^2+, and Fe^2+
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| Modulator | A factor that influences either protein binding or protein activity, such as pH/temperature/etc.
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| Two basic mechanisms by which modulation takes place | The modulator either (1) changes the ability of the ligand to bind to the binding site, or (2) changes the protein’s activity or its ability to create a response
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| Chemical modulators | Molecules that bind covalently or noncovalently to proteins and alter their activity. They may activate, enhance, inhibit, or completely inactivate the protein
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| Antagonists, AKA inhibitors | Chemical modulators that bind to a protein and decrease its activity, e.g. binding to the protein and blocking the binding site without causing a response.
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| Competitive inhibitors | Reversible antagonists that compete with the customary ligand for the binding site. The degree of inhibition depends on the relative concentration of the competitive inhibitor, the customary ligand, and the protein’s affinity
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| Irreversible antagonists | Bind tightly to the protein and cannot be displaced by competition.
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| Usefulness of antagonists | Antagonists drugs have been proven useful for treating many conditions, for example tamoxifen, and antagonist to the estrogen receptor, is used in the treatment of hormone-dependent cancers of the breast
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| Allosteric modulators | They bind reversibly to a protein at a regulatory site away from the binding site, and by doing so change the shape of the binding site
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| Allosteric inhibitors | Antagonists that decrease the affinity of the binding site for the ligand and inhibit protein activity
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| Allosteric activators | Increase the probability of protein-ligand binding and enhance protein activity
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| Covalent modulators | Atoms or functional groups that bind covalently to proteins and alter the proteins’ properties. Like Allosteric modulators they can either decrease or increase protein activity.
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| One of the most common covalent modulators | The phosphate group, and when it attached to the protein this is known as phosphorylation
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| One of the best known chemical modulators | Penicillin
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| How does penicillin work? | It’s an antagonist that binds to a key bacterial protein by mimicking the normal ligand. The protein is irreversibly inhibited. Without the protein, the bacterium is unable to make a rigid cell wall and it ruptures
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| Physical factors that affect protein activity | Temperature and pH are most common. Once they reach a critical value, proteins will begin to denature (i.e. lose conformation)
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| Example of denaturing in cooking | Cooking ceviche raw fish is marinated in lime juice. It has H+ ions that disrupt H-bonds in the muscle proteins of the fish, causing them to denature. The meat becomes firmer, just as it would if it were cooked with heat.
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| Is denaturation reversible? | In a few cases, activity can be restored if the original pH or temperature returns. Usually, however, denaturation produces permanent loss of activity. This is why it’s so closely regulated
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| Up-regulation | The programmed production of new proteins
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| Down-regulation | The programmed removal of proteins
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| Saturation | The state at which proteins have no more free binding sites
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| The four biomolecules | Carbs, lipids, proteins, nucleic acids
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| The monosaccharides we should know | Fructose (5-membered ring), glucose (6-membered), galactose (6-membered)
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| Disaccharides | Sucrose (glucose + fructose); Maltose (glucose + glucose); Lactose (galactose + glucose)
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| The linkage between disaccharides | Ether linkages
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| Is glycerol a lipid? | No, it’s a 3 carbon alcohol. It links with fatty acids to create lipids
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| Glycerol ______ to fatty acids to create lipids | Esterifies (definition: a reaction of an alcohol with an acid to produce an ester and water)
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| The two ends of a fatty acid: | Carboxylic acid end and methyl end (and a bunch of methylenes in the middle)
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| The 3 overall types of lipids that can be formed when a glycerol binds with fatty acids | Monoglycerides (one fatty acid); diglycerides (two fatty acids); triglycerides (three fatty acids)
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| Palmitic acid vs. oleic acid vs. linolenic acid | Palmitic = saturated; oleic = monounsaturated; linolenic = polyunsaturated
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| Storage form of fat vs. used for metabolism | The storage form of fat = glycerol + fatty acid. Once that linkage is severed, the fatty acids are in the form in which they’re metabolized. Note: a lipase will cleave the fatty off to be metabolized when needed
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| Amino acids come together to form | Proteins
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| Bonds between amino acids | Amide bonds – one of the strongest bonds in all of biochemistry.
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| The neutral amino acids: their R groups | Very small, like H or glycine.
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| The hydrophobic amino acids: their R groups | Large, hydrophobic R groups like in isoleucine and hydrophobic
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| The two amino acids that use sulfur | Methionine and cysteine
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| N-terminus vs. C-terminus | Amino (-NH2) vs. carboxylic acid (COOH) ends
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| Alpha carbon | Middle carbon in amino acid backbone
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| Arrange classifications of peptide sizes | Oligopeptides < polypeptides < proteins
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| Nucleotide composition | Base (e.g. purine/adenine), sugar, and either 3 phosphates or 1 phosphate
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Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
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You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
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